I'm the same. Can be useless at 100m sometimes :XD:Quote:
Originally Posted by veitnamcam
I'm the same. Can be useless at 100m sometimes :XD:Quote:
Originally Posted by veitnamcam
I believe he's referring to the fact that a bullet, once sent on its way will break the sound barrier somewhere along the length of the barrel whilst being accelerated by expanding propellant gases, then as drag from the atmosphere slows the projectile down, somewhere down range the projectile will pass back through the sound barrier a second time.Quote:
Originally Posted by vulcannz
That doesn't make sense, it's still the first sound barrier. Might've been easier to say "when the bullet goes subsonic".
If you have a fence in front of you, and you hop over it... you hopped over the first fence. You don't turn around and hop back the other and say "I hopped over the second fence" :)
I think what is meant is the disruption as the bullet starts to go trans sonic and then a further disruption at fully subsonic. It is not just and exact line to cross, more like a DMZ
It was actually proved / demonstrated by a Doctor in the USA around 1880 - 1900.Quote:
Originally Posted by blair993
Ok so we can have a good read up on the experiment. Shame no one told litz all about it.
Had a quick try to find it again, but from memory it was months of work with paper screens set up at different ranges so that a given string of shots produced groups at each range which could be compared. This work demonstrated shots moving away from the line of sight and then back and then travelling on a straight path.Quote:
Originally Posted by blair993
You can't see the glaring faults with that methodology?Quote:
Originally Posted by Moa Hunter
Sounds like Angelina Jolie's movie 'Wanted' :wtfsmilie:
bah- who needs physics.
I have given a simple three line summary of what I remember from reading. As the reference work was the result of some months of extensive testing would it be reasonable to expect that there was a fair bit of detail which my three lines does not cover ?Quote:
Originally Posted by Proudkiwi
The book is 'The Bullets Flight' by Dr F. W. Mann Published 1909. Check it out, first edition for sale for 180 pounds
Some info about Mann https://www.google.co.nz/url?sa=t&rc...aw15s1yDk1eHfe
A little more current testing.
from the Houston Warehouse. Very interesting reading.
Myths Busted:
Powder charges, as long as they were fairly consistent and bracketed within a couple of grains, were not important. He threw all of his charges with a Belding & Mull powder measure, and for one experiment he shot groups using three different powder measure settings (51, 52 & 53) … all three groups were identical.
Lot variation in powder didn’t seem to have any effect on accuracy, even on when using IMR 4198, which has a reputation for varying considerably from lot to lot. He would just buy powder as he needed instead of laying in a big supply, because he found no evidence to support that powder lot variance affected accuracy in the least.
He never saw an inaccurate primer, and was unable to detect any accuracy variances resulting from seating pressure.
Rumors have persisted for years that some rifles shoot proportionally better at 200 yards than 100 yards, or vice versa. Virgil files that one under “occultism.” His experience in the warehouse was, if a rifle was shooting a consistent .100″ at 100 yards, it shot a consistent .200″ at 200 yards.
Yeah Nah... Doctors in 1880 were handing out smokes as a cure for asthma, and arsenic to cure syphilis.Quote:
Originally Posted by Moa Hunter
In 1880 they used Mercury, it was 1909 that the 'Magic Bullet' was invented. Doesn't mean that a DR couldn't do some ground breaking work with ballistics.Quote:
Originally Posted by vulcannz
I am wondering if it has a lot to do with optimum twist rate for velocity ?
That pdf seemed to have more to do with mutilating bullets. Dunno bout the bullets but it sure put me to sleep lol!
https://web.archive.org/web/20120831...r_to_targe.pdf